This invention relates to a combination arc brazing torch and an arc welding electrode holder, and more particularly to such a combination electrode holder for use primarily with a welding power supply unit for use in a home work shop, garage, or farm.
Heretofore, arc welding apparatus has oftentimes been provided with a combination arc brazing torch and arc welding electrode holder. However, these prior combination electrode holders were difficult to manufacture and were, in many instances, too large and expensive for ready and economical application with smaller, inexpensive, light duty electric welding units.
In prior electrode holders, a spring loaded jaw-type clap has typically been used to clamp the electrodes in place on the holder. However, these prior electrode clamps were of necessity ruggedly constructed so as to hold the electrode firmly in place. The rugged design and construction of these prior electrode holding clamps resulted in electrode holders which were too expensive to use with smaller, less costly arc welding units. Still other less expensive electrode holders were known which used a screw-type clamp to hold the electrode in place. However, these screw-type clamps were cumbersome to operate, particularly when the user was wearing gloves, and were subject to being damaged (and thus eventually rendered inoperable) by their being spattered with droplets of molten metal during welding or by arcing if the welding electrode would inadvertantly be pulled from the holder during welding as may be occasioned by the electrode sticking to the work piece.
When using the holder as an arc brazing torch, it is necessary that a pair of carbon (i.e., graphite) electrode rods be held by the holder such that the ends of the electrode rods are spaced a desired distance so as to strike and to maintan an electric arc therebetween. In order to accomplish this, it is necessary that the electrode holder be capable of accurately adjusting the electrodes relative to one another and yet that the electrodes can be fed out as they are consumed. In certain of the prior art brazing torches, it was relatively difficult to adjust the relative position of the electrode rods.
Also, it was oftentimes necessary to securely hold a range of electrode sizes (i.e., range of electrode diameters). For example, the ends of electrodes to be clamped in the holder may vary in diameter from 1/16 to 1/4 inch (1.6 to 6.4 mm.). If the electrodes are not securely held in place by the holder, good electrical contact will not be maintained between the holder and the electrode and arcing may result with consequent damage to the electrode holder.